Tire 1
/ R
285
55
R20
Tire 2
/ R
265
70
R18

Odometer Reading

If you replace 320/60/18 with 235/60/18 for Odometer reading 1000 the actual distance traveled = 879 ~ (-12.1%)

(If your Odometer is accurate for original tires)

Edit and Copy Tire diagram above to compare or print.

Speedo Difference between Wheels 12.1%
320/60 R 18 KPH 235/60 R 18 KPH
5 4.4
10 8.8
15 13.2
20 17.6
25 22
30 26.4
35 30.8
40 35.1
45 39.5
50 43.9
55 48.3
60 52.7
65 57.1
70 61.5
75 65.9
80 70.3
85 74.7
90 79.1
95 83.5
100 87.9
105 92.3
110 96.7
115 101.1
120 105.4
125 109.8
130 114.2
135 118.6
140 123
145 127.4
150 131.8

Comparison Table

Section Width
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

285 mm
265 mm
Sidewall Height
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

6.17"
7.3"
Overal Diameter
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

32.34mm
32.61mm
Rim Size
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

Circumference
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

101.6 "
102.44 "
Revs per mile
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

623.62/mi
618.51/mi
Speedometer
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

Considering this is the manufacturer’s tire size and speedometer readings are correct.
Note: speedometer's 60km/h actually mean 60 km/h
Car height
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

Basic
+3.4 mm
Typical Weight
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

56.2 kg
46.7 kg
Ground Clearance
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

Stock
+3.4 mm
Tire with the same height
i

The TrueContact Tour is Continental's Standard Touring All-Season tire developed for drivers of family sedans, coupes, minivans and small

Performance
Result
Impact
Design
Worsen
Your car is visually less appealing with less prominent disks and narrow tires. If you care about the looks of your vehicle, think about the size of your disks.
Road holding ability
Worsen
Insufficient road grip. The degree of improvement in traction is largely determined by the aspect ratio of the wheel. In addition, reducing the width of the tires increases the braking distance on dry pavement. This happens because the tire-to-road contact area is reduced.
Precision of steering response
Worsen
The steering is slow and the cornering is poor. If your rim diameter is smaller and your tire height is higher, for example, you'll have reduced control of your vehicle while cornering and also decrease the speed you can safely take such turns.
Grip on dry pavement
Worsen
The contact patch of narrower tires is reduced, reducing traction on dry pavement.
Grip on wet pavement
Enhance
A narrower tire, which can expel more water from underneath the wheel, improves braking performance on wet pavement.
Grip on dirty surfaces
Enhance
Enhanced grip on muddy roads. When driving on sandy or dirty roads, less contact area is almost directly proportional to less braking distance.
Hydroplaning resistance
Enhance
Hydroplaning resistance has been improved. The contact area of the road surface is smaller when the tire is higher and narrower. The tread does not need to expel as much water from beneath the wheel.
Ride comfort and noise
Enhance
Comfortable riding. Traveling on tires with a higher profile is more comfortable than on tires with a lower profile. Noise levels are reduced. A reduction in tire width nearly always reduces tire noise, but it depends on the tread compound and shape of the tire. Because of the reduced travel distance between the tread blocks, air moves faster between them.
Fuel consumption
Decrease
Fuel consumption is significantly reduced. The rolling resistance of narrower tires is lower, which reduces fuel consumption.
Treadwear
Enhance
Reduced risk of tire and rim damage. The sides of tires with a higher profile are less likely to be damaged than those with a low profile.
Cost
Decrease
New rims and new tires are always an expensive investment, particularly since larger rim diameters are more expensive. Additionally, advanced materials and complicated tire construction methods are required to reduce tires height and increase their tread width. In turn, this causes the final product to be more expensive.
Weight
Increase
Generally, wheel weight is included in the overall weight of your vehicle. Cars that are lighter will be able to accelerate more easily and slow down more easily when necessary. They will also consume less fuel overall.

Popular comparisons



Amazon Associates Program

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
We may earn a commission from links that lead to the Amazon site.